2007 Ford expedition spark plugs: should I replace some or all of them?

[truckguy]

My car went through this:
https://www.expeditionforum.com/thr...-violently-when-turned-on-this-morning.42302/
I ended up paying $5400 for that fix (camshaft, roller, valves, etc)

After that, I drove it a few times and only noticed a bit of rough idling when I start the car, which becomes a bit smoother after driving some time. Since now I'm replacing the IMRC and have everything out of the way, I decided to check the spark plugs. Took them off and they look like this:

As you can see, 7 out of 8 are the same design, while the right most guy has a bit different design. They are all motorcraft platinum plugs. I've roughly cleaned them with a paper towel, but you can still see some black stuff on the plugs for some of them (carbon?), mainly from driver side of the engine. Passenger side plugs looked better. Overall the plugs' electrodes looks not to be worn out.

I'm wondering if I should replace these or keep using them. Or maybe I should replace some?

Also should I be concerned about the black stuff around the plugs? Would sea foam help clean that out?

My ignition coils looks to be in good shape (showing 2 out of 8 here):

 

[WEDGE]

If you don't know how old they are, and all 8 came out without breaking, I'd change them all!

 

[WEDGE]

If you don't know how old they are, and all 8 came out without breaking, I'd change them all!

 

[Thunderbirdsport]

^This. And be sure to replace them with the updated design.

About a year ago I decided to replace the plugs and coils in my '06 Explorer (4.6 3v, pretty much the little brother of what the Expy's have), and I was rather dreading it because mine is within the years that had the plug issues twisting off.

To my surprise, a previous owner had replaced them with the updated units, and to add to that they were barely tight.

I put new ones in along with new coils, and holy shit, what a difference.

 

[truckguy]

Thanks replaced all of them.

 

[07navi]

Those were original pzh 14's, luckily you got them out.

 

[FlaRay]

Change em, less headaches down the road